Electronic firing mechanism



y 1969 e. GROLLEAU 3,453,764

ELECTRONIC FIRING MECHANISM Filed June 23, 1967 Sheet of 2 INVENTOR:GERARD GROLLEAU y 9 G. GROLLEAU 3,453,764

I ELECTRONIC FIRING MECHANISM Filed June 23, 1967 Sheet of 2 INVENTOR:GERARD GROLLEAU ATTORNEY United States Patent ,26 Int. Cl. F41c 19/12US. CI. 42-84 3 Claims ABSTRACT OF THE DISCLOSURE In an electronicfiring mechanism, an electro-magnet actuating a magnetizable lever, anautomatic circuit closing contact, the opening of which makes conductivea transistor energising the electro-magnet and operating the firing pin.

Already known are firearms with electrical or electromagnetic firingmechanisms. The electro-magnet in such mechanisms is energised by theclosing of a circuit with the aid of a contact made by the user. Inorder to fire, the user presses on the trigger to bring together theelectrodes into contact.

The path which the movable electrode must travel is determined by thespace between the two electrodes, this results in a time lag until thecontact be effective, with a resulting loss in accuracy. During thistime the arm may be moved by the operator.

Moreover, it is necessary that the space be constant and accurate. Ifthe same varies, there will be variations in firing time. Additionally,foreign bodies can become lodged between the electrodes, preventingcontact with occasioning firing accidents.

The present invention remedies all these disadvantages and permitsabsolutely instantaneous firings which are extremely precise andreproducible owing to its principle of operation which is based upon thebreaking of a con-- tact, that is to say upon the moving apart of theelectrodes.

To this effect, the invention is concerned with a trigger for firearmscharacterized by electronic means adapted for instantaneously causing,by opening of a contact, the energising of the electro-magnetcontrolling the movement of the firing pin.

According to a characteristic of the invention, the electronic meansconsist of a battery, a condenser, a resistance, a transistor, anelectro-magnet, a switch and a starting member.

According to another characteristic of the invention, the firingmechanism is constituted independently of a support, a hammer and aspring, a hammer sear, a spring, a trigger and its pivot pin, anadjustable stop screw with its blocking counter screw and a guidingscrew.

According to another characteristic of the invention, the triggercomprises a safety mechanism composed of a lock and of its spring.

The invetnion will be better understood by referring to the accompanyingdescription made by way of non limiting example and to the drawing inwhich:

FIGURE 1 shows the electronic firing mechanism in percussion position,

FIGURE 2 shows the electronic firing mechanism in its cocked position,

FIGURE 3 shows a transversal view of the firing pin mechanism and a lockin safety position.

The various electric members adapted to the voltage used are connectedin the following manner (FIGURE 2).

A conductive wire 31 going from the positive terminal 32 of battery 6connects the starting command 4 at its sup- 3,453,764 Patented July 8,1969 porting point 34 which is insulated from the mass of the firearm.On this wire 31 is connected a terminal 33 of condenser 28 as well asthe emitter 39 of transistor 2. Then starting from support 34 current isdirected to electrode 5 by means of a spring blade on which it issecured, current being transmitted to the fixed electrode 5 which servesas a stop for the movable electrode 5 Then starting from the fixedelectrode 5 the latter being insulated from the starting member 4,another conductive wire 35 conducts the current to a terminal 36 ofresistance 29 and to the base 37 of transistor 2 on which these latterare connected.

On the other hand, a conductive wire 26 starting from the negativeterminal 27 of battery 6 conducts current to switch 19 (automaticcircuit cutting contactor) on which is connected the other terminal ofcondenser 28 and of resistance 29 as well as the entry wire ofelectro-magnet coil 1. Finally, the outlet wire of said electro-magnetcoil 1 is connected to the emitter 30 of transistor 2.

The circuit is closed when the arm is ready to be fired. The heel ofhammer 8 in the cocked position maintains in contact the electrodes ofswitch 19 as shown in FIGURE 2. At the other end, the electrodes of thetrigger 24 are in permanent contact. Current is weakly absorbed bytransistor 2 without passing into electro-magnet coil 1.

The electrical circuit is broken by pulling on trigger 24 in thedirection of arrow A. The electrodes 5 and 5 move away from one another,transistor 2 then allows the passage of current to electro-magnet 1which is thereby energized and triggers th percussion by attracting toitself a pivoted magnetizable lever 12. Percussion takes place andhammer 8 which actuates the percussion means as well as switch 19 leavesthe circuit open. It is only when the percussion mechanism is againcocked that the electrical circuit will again be closed.

It can readily be seen that the present system is also readily adaptableto small arms since in such arms it is not possible to readily install aconventional system which is percuted by the direct action of anelectro-magnet whose core is propelled. This naturally requires apowerful electric magnet which in turn needs a large energy source.

Referring to FIGURE 1 the percussion mechanism is composed of a support7, a hammer 8 and a spring 9, a hammer sear 10, a common spring 11, anadjustable stop screw 14 with a blocking counter screw 15 and a guidingscrew 16. Spring 11 is compressed in a housing formed by mutually facingcut outs in lever 12 and sear 10. It will be noted that the front partof the cut out in sear 10 is formed by a part which is in contact with alocking part forming the front side of the cut out in lever 12.Obviously when lever 12 pivots upon being attracted by theelectro-magnet 1, these two elements will no longer be in contact andsear 10, no longer locked, will release hammer 8. The arming of thetrigger and percussion mechanism takes place simultaneously in thefollowing manner.

The arming lever 17 is brought back in the direction of arrow A bygrasping with the index finger the extremity 50 of the lever whichprojects outside stock 38 (FIGURE 3). The same pivots then on its pin 18and thanks to its pin 52 applied against the front face of hammer 8,drives the same rearwardly and thus compresses its spring 9.

This rearward movement is continued until thebolt of the arming levercomes to strike against the edge of a notch made in the upper wall ofthe support piece 7 (not shown) to permit on the one hand its passageand on the other hand determine its stop when it comes in end of courseagainst a stop. FIGURE 3 shows the safety lock 21 in the safetyposition. There can be seen in this figure the inwardly directed pin ofarming lever 17 which is located in front of hammer 8 as well as thepart of the same lever which is accessible on the outside of the Weapon.The

safety lock 21 has a spring 22 which urges it in front of hammer 8 andopposes its movement. When the arming lever 17 is pushed forward to theposition shown in FIG- URE 1, the heel 54 thereof meets the chamferedhead of lock 21 and causes the same to retract thereby allowing passageof hammer 8. The weapon is then ready for percussion. Movement of arminglever 17 causes lock 21 under the urging of its spring 22 to again movein front of the hammer and prevents it from moving. When the arminglever 17 is moved in the direction of arrow B, the heel 54 thereof againmeets the chamfered head of lock 21 which projects in front of it andforces it to retract inside its housing.

To replace the safety lock when the weapon is cocked the arming lever isbrought back in the direction of arrow A until the noise produced by thepenetration of ball 23 in a recess provided in the inner surface of thelever is heard. This sort of locking of arming lever 17 defines aposition thereof which allows its heel to free the safety lock 21 and toallow the same to move in front of hammer 8 and thereby again preventpercussion.

It will be appreciated that in-the locked position, the rear part of thehammer maintains the electrodes of switch 19 in contact with one anotherto-establish the circuit.

A predetermined movement of pieces 8 to 10 and 12 has taken placemeanwhile and the engagement of said members corresponds at the stoppingpoint of lever 17. It is thus that the notch made on the lower part ofhammer 8 is located on a level with the head of sear 10. The lattermoves upwardly against the urging of its spring 11 in the direction ofarrow C, making possible the hooking of hammer 8. At this moment thehead of lever 12 which forms a locking member is free and places itselfunder the heel of sear 10 (to prevent it from going down again) in arotational movement around its shaft 13. This movement is limited by theadjustable stop screw 14 on which the lower part of lever 12 comes tobear against the urging of the same spring. It is maintained constantlycompressed between the head of trigger 12 and sear 10 in which it islodged. At the end of its travel, in its rearward movement, the rearextremity of hammer 8 projects outside its housing, in an opening madein the supporting piece 7, and meets a micro contact blade of theautomatic circuit cutter 19 to drive it in order to apply it against itsother contact point, thus permitting to establish the electrical circuit.

When the simultaneous and successive engagement of all the members 8, 10and 12 is made, the arming lever is moved forward in the direction ofarrow B in order to place it in its inoperative position. The hammer 8is thus maintained in armed-position ready to strike the firing pin 20.

The present invention has numerous advantages:

The electronic trigger permits an absolute instantaneous operation sincethe tripping occurs at the moment of the cut olf (opening of theelectrodes); there is thus elimination of the time lag represented bythe path to be covered in order to travel over the spaced apartelectrodes to make contact as in previously known systems. It permits toobtain a constant precision. The adjustment of the resistance (normallycalled sensitivity) cannot modify the spacing of the contacts.

The mechanism is practical and fool proof.

Perturbations in the operation due to foreign bodies coming betweenelectrodes with irregular spacing, and adjustments are eliminated.

The percussion mechanism is very simple and easy to fabricate. Ineffect, the parts are not complicated and are reduced to a hammer, asear and an arming lever.

With the exception of the arming lever, all parts of the percussionmechanism are cylindrical and can be mounted in a very simple housing.

The present mechanism eliminates critical engagement points of parts andthe exact determination of distance between the centres, while reducingthe number of spring needed.

All the percussion members are housed in a casing. They are thusprotected from dust and from all factors which might prevent or modifytheir movement.

The mechanism constitutes an interchangeable compact unit which isreadily accessible to the operator.

It is of sure functioning and is not sensitive to time lags resultingfrom inertia. The safety functions automatically by means of a singlearming lever.

What is claimed is:

1. Electronic firing mechanism comprising an energizing circuitincluding a source of current and a transistor fed by said source; anelectro-magnet, a switch having electrodes for feeding current from saidtransistor to said electro-magnet upon opening of said circuit;percussion means; a hammer movable between a front position in contactwith said permission means and a rear position in which it maintainssaid electrodes in contact, a first spring urging said hammer towardsaid means, an arming lever having an externally accessible portion andan inwardly projecting portion in contact with said hammer for movingsame; a pivoted magnetizable lever having a locking member, a sear forholding said hammer, said sear being held against said hammer by saidlocking member to maintain said hammer in said rear positions; a safetymechanism comprising a lock spring urged toward said arming lever andretractable thereby, said lock having a part projecting in front of saidhammer; trigger means for opening said circuit and energizing saidelectro-magnet and thereby attracting thereto said magnetizable lever,causing References Cited UNITED STATES PATENTS 2,780,882 2/ 1957 Temple4284 2,957,391 10/1960 Lovercheck 4284 3,208,181 9/1965 Calhoun et al.4284 3,250,034 5/1966 Simmons 4284 BENJAMIN A. BORCHELT, PrimaryExaminer.

